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Percutaneous transhepatic cholangiography (PTC)

In this diagnostic procedure, a needle is introduced through the skin and into the liver where the dye (contrast) is deposited and the bile duct structures can be viewed by x-ray.

Photodynamic Therapy (PDT)

This treatment method is used to open up esophageal blockages or treat small, shallow tumors in patients who cannot tolerate open surgery. In PDT, a drug called a photosensitizer is administered intravenously and preferentially absorbed by cancer cells over a few days. Using an endoscope, the surgeon exposes the lesion to a certain wavelength of light, which causes an active form of oxygen to be produced. This directly kills the cancer cells and also acts indirectly to damage the tumor's blood vessels, further destroying the cancer and limiting damage to surrounding healthy tissue. PDT cannot be used for large or deep tumors. Risks include light sensitivity for about six weeks after treatment, trouble swallowing after treatment, swelling, pain, or scarring in healthy tissue.

Surgeons may also place a stent in the esophagus to open up any blockage and enable more comfortable swallowing.

Positron Emission Tomography (PET Scan)

For a PET scan, patients are given a very small dose of radioactive material, either in a liquid to drink, or as an injection, which is followed by a gamma camera and computer. Because PET scans measure blood flow, oxygen use and sugar metabolism, physicians are able to accurately determine whether a lesion is cancerous or not, because cancer has characteristic blood flow and metabolism patterns. PET scans help determine whether or not surgery is recommended after diagnosis. They can also help determine whether a treatment is working, and after treatment, whether a patient has a recurrence. The PET scan can reveal answers to these important questions much sooner than other types of scans.

Proctosigmoidoscopy

Examination of the lower colon using a sigmoidoscope. See Sigmoidoscopy.

Pyloroplasty

This surgical procedure may be performed along with a vagotomy (a surgical procedure which involves cutting the vagus nerve in the stomach to reduce acid secretion), in which the opening into the duodenum and small intestine (pylorus) are enlarged, enabling contents to pass more freely from the stomach.

pH monitoring

An esophageal pH monitor measures the acidity inside of the esophagus. It is helpful in evaluating gastroesophageal reflux disease (GERD). a thin, plastic tube is placed into a nostril, guided down the throat, and then into the esophagus. The tube stops just above the lower esophageal sphincter, which is at the connection between the esophagus and the stomach. At the end of the tube inside the esophagus is a sensor that measures pH, or acidity. The other end of the tube outside the body is connected to a monitor that records the pH levels for a 12 to 24 hour period. Normal activity is encouraged during the study, and a diary is kept of symptoms experienced, or activity that might be suspicious for reflux, such as gagging or coughing. The pH readings are evaluated and compared to the patient's activity for that time period.

Proctocolectomy

a proctocolectomy - removal of the entire colon and rectum - is the most common surgery for ulcerative colitis. Since ulcerative colitis involves only the large bowel, this operation is considered curative. a proctocolectomy is combined with ileostomy, which creates a small opening in the abdominal wall where the tip of the lower small intestine, the ileum, is brought to the skin's surface to allow drainage of waste

Proctoscopy

During proctoscopy, a lighted tube is inserted into the anus, allowing the physician to completely examine the entire rectum.